1. Technical Field
The present invention relates to a light emitting element, a light emitting device, and an electronic device.
2. Related Art
An organic electroluminescence element (a so-called organic EL element) is a light emitting element with a structure where a light emitting organic layer with at least one layer is interposed between an anode and a cathode. In the light emitting element such as this, through the application of an electric field between the anode and the cathode, in the light emitting layer, a hole is injected from the anode at the same time as an electron is injected from the cathode, therefore an exciton is generated by the reunion of the electron and the hole in the light emitting layer and the energy is released as light when the exciton returns to the ground state.
As a light emitting element such as this, an element which emits infrared light in the near-infrared region at a long wavelength region greater than 700 nm is known (see JP-A-2000-091973 and JP-A-2001-110570, for example). For example, in a light emitting element disclosed in JP-A-2000-091973 and JP-A-2001-110570, an emission wavelength is made longer by using a material, in which, an amine as an electron donor, and a nitrile group as an electron acceptor, co-exist as functional groups in the molecule, as dopants of the light emitting layer.
However, in the related art, an element with high efficiency and a long life, which emits light in the near-infrared region has not been able to be achieved. Therefore, realization of a light emitting element including a light emitting layer which emits light in the near-infrared region and a light emitting layer which emits light in the visible region may also be considered, however, if applied to the light emitting element such as this, long-term light emission in the visible region has been able to be achieved but long-term light emission in the near-infrared region has not been able to be achieved.